COVID-19: TEST TRACE AND ISOLATE (A CRITIQUE)

We’ve looked at the different types of tests, and their value.  That leaves us with the big issue, which is Test, Trace and Isolate.  Is the approach in England on the right track?  Or would it be better to do something else?

Testing and tracing only has value if the people tested positive and their contacts self-isolate, so they do not pass on the virus to other people.

Calling the process “NHS Test and Trace” without “Isolate” immediately throws up a warning flare that the very basics of the process are misunderstood in England, and/or are being poorly communicated to the public. .

In theory Test Trace and Isolate (TTI) is a vital component of reducing transmission of COVID-19.  That is alongside, social distancing, the use of masks and washing of hands and surfaces.  But people keep saying TTI is “critical”.  Is it?

Sadly national TTI for COVID-19 is inherently never going to be effective:

• With the technology available
• The need to test non-infectious people to be truly effective
• Plus various other problems, discussed below. 
• And horrendously expensive, with a figure of £10 billion being spent by government  

There has been much criticism of NHS Test and Trace.  At the national level, it is clearly a waste of money, with little chance of getting better the way it is currently organised.  TTI’s value is when everybody can be tested, whether they are displaying symptoms or not.  In practice that can only be done at a local level.  If the general level of infections is very low, when there would be only a small number of local surges, TTI then becomes the national strategy.  That is what Professor Chris Whitty, England's Chief Medical Officer, suggested back in March.

It is a great pity that the World Health Organisation is working from a text book by saying “Testing, tracing must be 'backbone' of coronavirus response” without considering the practical issues that can only result in failure for such an approach with COVID-19. 

Scotland officially recognises the practical considerations when they say
“To allow for a "test, trace, isolate, support" approach to work, the levels of disease need to be sufficiently low to make the management of outbreaks the exception rather than the rule.”


THE PRACTICAL PROBLEMS IN ENGLAND

Let’s look at each aspect of testing, tracing and isolation:


Testing

We know that for testing to be effective it needs to be:

• Reliable
• Simple
• Quick, to confirm infection as soon as possible
• Cheap
• Applied to everyone, symptomatic or not

The current RT-PCR testing, as explained here, is:

• Unreliable, especially when swabbing is used, producing over 30% in ‘false negatives’
• Complex
• Slow, measured in hours and days, not minutes
• Expensive, especially if false results have to be re-tested

The RT-LAMP technology is producing tests which improve simplicity, timeliness and costs.  But is still at least £20 a test, and just as unreliable until an alternative to swabbing can be found.


The current technology simply isn’t the basis for a national TTI strategy, until it can be focused just on local surges, as Scotland acknowledges.


Tracing

A couple of weeks ago, a friend who I had met at an outdoor function dropped me a message that they were now displaying symptoms of COVID-19.  Could I have caught it from them?  A daunting thought, given I am self-employed and can’t afford to let any new work opportunities pass me by.  I could miss a new client and years of work for them!

If we do become symptomatic, we know our household, colleagues and others who we know we have met in the preceding days.  A friend caught COVID-19 from attending a choir rehearsal, and it was obvious who had attended.

But we have no idea who we have met on public transport, in a shop or other setting.  Especially indoors, which has been shown to be far riskier than outdoors.

The Contact Tracing App, trialled in Isle of Wight, was meant to fill this gap.  But this was withdrawn as being ineffective.  Some of the inherent problems are:

• If we were infectious, we don’t know who of the many people we might have passed have been with us long enough and close enough to be likely to have caught COVID-19 from us
• We don’t know how many days ago we started to be infectious
• We might be very close to someone the other side of a party wall between terrace houses, or between units in multi-occupancy premises, but with no chance of transmission of the virus
• Delivery personnel meeting dozens of people a day

It would be possible to put assumptions into the app’s logic, but inevitably people would be included who wouldn’t have caught the disease, and conversely ignoring people who would have caught the disease.

There are then several issues with using an app:

• It is only available to people with smartphones
• Who are prepared to download and use the app
• What’s to stop people not bothering to say they are symptomatic, or falsely saying they are?
• Privacy concerns about being tracked, and how the data would be used

With some many fundamental issues with an app, it was disappointing but no surprise that the trial was discontinued.

There are also privacy issues with people who are tested not wanting to disclose their real contact details, and who they have been with.  May in part explain the relatively low level of contacting people to establish their contacts, and then being able to contact them.


Isolate and Support

There is no point asking people to isolate if they cannot confirm they are COVID-19 carriers.   At the moment testing is not officially available until someone displays symptoms.

If you are self-employed or on a zero hours contract knowing whether or not you have COVID-19 is essential, as is financial support if a test proves positive.  That can also be relevant to employees, especially if it could make them susceptible to redundancy.

For everyone there is also the need for practical support:

• Being able to get food for the period being asked to isolate.  Not everyone has two or three weeks food in the house
• Ideally to isolate in premises separate from other members of the household, to reduce the risk of infecting them.  This has been shown to be the largest proportion of transmissions, so well worth tackling.

In any case, how do we know that the people who need to self-isolate are doing so?  We don't.


In Summary

There are major problems with each aspect of Test Trace and Isolate:

• Testing unreliability and expense, which doesn’t identify those who might be infectious but not symptomatic
• Tracing which fails to identify contacts, and fails to contact those identified
• Isolation without adequate support or follow-up

TTI is therefore impractical and inherently an expensive waste of money if attempted at a national scale, as being done for NHS Test and Trace.

Scotland has the right idea that TTI can only work if:

• The general level of infection is very low, so there are only a small number of local surges
• For local surges, everyone can be tested
• Local tracers can deal with their own local community
• Those asked to isolate are tested, and given adequate practical and financial support

Indeed TTI can only work effectively for local surges, within a very low level of national infections.  Just as Scotland have realised.  England needs to follow suit.

It is also means that that at the national level,  TTI cannot be the 'backbone' of the COVID-19 response.  Reducing the national level of infection to a very low level, and keeping it very low, will need to be primarily as a result of a combination of other anti-transmission measures:

• Social distancing
• Masks and face coverings
• Washing hands and surfaces
• Not allowing certain activities, such as large gatherings
• If necessary, general lockdowns at local or national level
• Coupled with a much stronger public education campaign than we have seen so far

WHAT ABOUT THE NATIONAL CONTACT TRACERS?

Reports are that many of the national contact tracers are twiddling their thumbs for much of their day.  These are employed by a commercial organisation with which the government will have a contract.

As the national TTI, “NHS Test and Trace”, is inherently an expensive waste of time, ideally you would find a way to unwind all the contractual commitments as cheaply as possible, and close the scheme down.

But that might prove very expensive.

As noted above, there needs to be a strong public education campaign.  Ideally this would include ‘wardens’ who like ari raid wardens of the second world war, could help educate, encourage and if necessary chide the public. Why not quickly redeploy contract tracers in this ‘warden’ role?

Update 11/8/20: No sonner said than done.  Many of the contracts tracers have indeed been released , and others redeployed as 'shoe leather' tracers knocking on people's doors.  This doesn't necessarily mean that some or all can't also have a 'warden' role.   That's still an idea.


IN CONCLUSION

The way England has set up the NHS Test and Trace is inherently going to fail, expensively.  That is what has happened, and it should be recognised that adequate improvements are not practical.  It would be throwing good money after bad.  The scheme as currently envisaged should be closed down.  As of 11 August, steps to do this have already started.

Scotland’s lead should be followed to:

• Get the background level of infection down to a very low level
• Focus on TTI for local surges, using local tracers

The existing national contact tracers could then be released, as has happened, or redeployed in a role that combines local 'shoe leather' contact tracing, knocking on doors, with being COVID wardens.  They could  help the public to comply with good anti-transmission practice in social distancing, masks and washing.

PM Johnson coined the term “Hands, Face, Space”.  That needs to be the focus of the national strategy, and leave local TTI to tackle local surges.